Initial-state relaxation effects in molecular Auger spectra

Abstract

The initial-state valence relaxation of the molecular orbitals to the presence of the core hole is found to have a significant effect upon the core-valence-valence Auger decay probabilities and hence upon the Auger line shape. Comparisons are made of experimental and theoretical line shapes of ammonia and ethane. The best theoretical amplitudes were calculated by using self-consistent initial-state molecular orbitals which were projected upon the final states. The use of explicit initial-state orbitals leads to significant improvement over a simpler approach consisting of the use of minimum basis set ground-state orbitals and atomic Auger matrix elements.